Compound pressure-engine.



No. 678,820. Patented July as, l90l.

M. L. WHITFIELD.

COMPOUND PRESSURE ENGINE.

. (Appiination filed Oct. 7, 1898.) (Nb Model.) 3 sham-sheet 1|.

T Vziizeased: jam Z07" wi y No. 678,820. Patented Iuly I6, ISIIII. M. L.WHITFIELD.

.GOMPOUND PRESSURE ENGINE.

(Application m'ea Oct. 7. 1898.)

(No Modal.) 3 Sheets-Sheet 2. X I ,ZEQg Q I l {I l p/ I: l 5 J? J E k"If-l five/e201 No. 673,820. Patented July I6, l90l.

M. L. WHITFBELD.

COMPOUND PRESSURE ENGINE.

(Application filed Oct. 7, 1898.)

(No Model.) s Sheets-$heet a.

Jizavzztqr a ur MARCY L. WHITFIELD, OF MEMPHIS, TENNESSEE, ASSIGNOR, BYDIRECT AND MESNE ASSIGNMENTS, TO THE WHITFIELD COMPANY, OF LAKE- VIEWV,MISSISSIPPI.

COMPOUND PRESSURE ENGINE.

SPECIFICATION forming part of Letters ratent No. 678,820, dated July 16,1901.

Application filed October 7, 1898.

T to 1072/0711, it may concern.-

Be it known that I, MARCY L. WHITFIELD, a citizen of the United States,residing at Memphis, in the county of Shelby and State of Tennessee,have invented a certain new and useful Compound Pressure-Engine, ofwhich the following is a specification.

This invention has relation to that type of steam or like motive-fluidengines known as trunk or telescopic engines, comprising a stationarylow-pressure cylinder, a stationary abutment or piston, and a mainmoving hollow piston working in said stationary cylinder and on saidstationary piston and constituting the high-pressure cylinder anddriving element of the engine.

The invention has for its object certain im-' provements in the type ofengines referred to, hereinafter fully described, and specifically 2opointed out in the claims.

In the drawings, Figure 1 is a longitudinal sectional View of a verticalengine embodying my present improvements; Fig. 2, a side elevation ofthe same; Fig. 3, a side elevation of a horizontal engine embodying mypresent improvements; Fig. 4, a side elevation of the plunger whichcooperates with the high-pressure cylinder formed in the piston; Fig. 5,a top View of said plunger; Fig. 6, a

.30 section on the line 6 6 of Fig. 1; Fig. 7, a side elevation of themain piston removed from its cylinder, and Fig. 8 a similar view takenat right angles to Fig. 7.

In all of the above views corresponding 3 5 parts are represented by thesame letters and numerals'of reference.

The engines illustrated in Figs. 1, 2, and 3 are in general respects ofwell-known vertical and horizontal types.

My present improvements can be applied to all forms of motor devices inwhich the movement of a reciprocating piston performs work, and includesnot only motors for driving rotating shafts, but also industrial tools-5 such as rock-drills, pluggers, &c.wherein the reciprocations of thepiston perform the work directly.

A represents a cylinder which is of the desired diameter and which is ofany suitable type. This cylinder is closed at one end by Serial No.692,902. (No model.)

a head B, secured in place in the usual way. At the side of the cylinderA is a valve-chest 0, containing a suitable valve,one illustration ofwhich will be described.

The valve-chest C is provided with a head X at one end and with aguide-box at the other, in which a valve-stem e reoiprocates.

I illustrate within the valve-chest C a 1101 low balanced slide-valve E,fitting snugly within the valve -chest. Leading into the valve-chest Cis a high-pressure steam-pipe 1, which cooperates with an annularchannel or pocket 2 on the valve E. This pocket or channel is adapted toplace the high-pressure pipe 1 in communication with a port 3 in theWall of the cylinder and through which steam will be admitted to thehigh-pressure space F. The said valveE is also provided with apocket orrecess 4:, adapted to be placed in communication with the port 3, andwith a third annular pocket or recess 5, adapted to be placed incommunication with a port 6 in the main cylinder leading to thelow-pressure space G therein. The valve E is adapted to place the port 6in communication with an exhaustpipe 7 ,through which steam maybeexhausted from the low-pressure cylinder. The valve E is provided with achamber h therein, and the annular pockets or recesses 4 and 5communicate with said chamber by means of small openings 8. Thevalve-stem e is operated in any suitable way-as, for example, by aconnecting-rod M, connected to an eccentric N on the shaft P.

Although valve mechanisms differing in form from that which I havedescribed may be employed, yet I prefer said described valve mechanismon account of its great simplicity and its not being liable to get outof repair.

Mounted in the cylinder A, so as to recip- 9o rocate therein, is a longpiston D,which for purposes of lightness may be provided with a chamber19 therein. The high pressure cylinder or space F is formed within thispiston, and in line with the port 3 the piston is provided with alongitudinal recess H, by means of which the said high-pressure spacewill be maintained in communication with said port during the movementof the piston for the reason to be explained. 10o

nected at their lower ends to a wrist-pin L,

on which a connecting-rod l is mounted, the said connecting-rod engagingwith the crank O on the shaft P, which latter may, if desired, beprovided with one or more fly-wheels Q. Mounted within the piston D andmaintained stationary with respect to said piston is a plunger J, theupper end of said plunger forming one end wall of the high-pressurespace F. The plunger J is provided at its outer end with a flange j,having two recessesj therein, in which recesses the arms' K of thepiston are adapted to reciprocate. The flange j of the plunger J isbolted to extensions I of the cylinder A, such extensions being providedwith flanges i 2', which coincide with the flange j, and between saidflanges it are the spaces corresponding with'the recesses j and in whichthe arms'K reciprocate. By mounting the arms K of the piston between theextensions I of the cylinder I obtain an effective guide for saidpiston, by which it will always be maintained in the proper alinementwith the cylinder. If desired, the bed-plate S of the engine may beprovided with extensions T, having flanges t, which coincide with theflanges 'i and j, all of said flanges being secured together by the samebolts. The bearings It for theshaft P may be of any suitable character.The piston D and the plunger J will be preferably provided with suitablepackings p, by which the necessary tightness of the joints will besecured.

An engine such as I have thus generally described and which is aconvenient illustrative type ofmy invention will operate as follows:With the'position of the parts shown in Fig. l the piston D hascompleted its high pressure stroke, the high --pre"ssure steam has beencut off by the closing of the port 3 from the pipe 1, andthe valve E isabout to be moved quickly upward to bring the pocket or recess at inline with said'port and to bring the pocket or recess 5 in line with theport 6. This movementof 'the'valve takes place just as the crank passesthe deadcenter. Steam from the high-pressure chamber will, thereforepass upon "expansion through the pocket H,'port 3,-recess 4,;per-

7 E will be shifted quickly to cut-oif the port fora-tions 8,cha'mber h,perforations 8,-pocket 5, and port 6 into the low-pressure cylinder G,and by reason of the larger diameter of that space thesteam in expandingwill force the piston toward theplunger J, completing one half-stroke ofthe piston. When the piston has completed this stroke and'as the crankagain passes its dead-center, the-valve 3 from the pocket 4'and to placethe pocket 2 in communication with said iport, said pocket being alwaysin communicationwith the high-pressure pipe. High-pressure steam willtherefore enter the highpressure cylinder and working against thestationary plunger J will force the piston D toward the cylinderhead B,thus completing the other half-stroke of the crank. During this movementthe port 6 will be in communication with the exhaustpipe 7, and theexhaust from the low-pressure cylinder will thus be secured. Byproviding the piston D with an extended longitudinal pocket H thehigh-pressure steam may be admitted to the high-pressure cylinder at alltimes irrespective of the position which the piston may occupy withrespect to the port 3. The same is true when the steam in expandingpasses from said high-pressure cylinder into the low-pressure cylinder.

Having now described my invention, what I claim as new, anddesire tosecure by Letters Patent, is as follows:

1. he compound engine, the combination of'a main inclosing cylinder, ahollow piston mounted in said cylinder whereby the space between thepiston and the cylinder head forms a low-pressure chamber, a relativelystationary plunger mounted within the piston whereby the space betweenthe pistonhead and plunger forms a high-pressure chamher, a port in thecylinder, an elongated between the piston and the cylinder head forms alow-pressure chamber, a relatively stationary plunger mounted within thepiston whereby the space between the piston-head and. plunger forms ahigh-pressure chamber, a port in the cylinder, an elongated pocket onthe piston in perpetualcommunication with said port whereby steam may beadmitted into or expanded from the high-pressu re chamber during themovement of the piston, and a hollow cylindrical slide-valve havingpockets therein arranged to be brought into coincidence with said portand with a port leading to the low-pressure chamber, said-slide-valvehaving a high-pressure pocket or recess 2 therein by whichsteam may besuccessively admitted to and cut off from the high-pressure chamber,substantially as set forth.

In a compound engine, thecombination ofa cylinder, a hollow pistonmounted therein, aplunger working in said piston, a valve mechanism foradmitting steam intothe highpressure chamber-and for allowing steam toexpand from the high-pressure chamber into the low-pressure chamber,extensions carried by the cylinder and to which said plunger isconnected, and bifurcated arms on the piston working in and guided bysaid extensions, substantially as set forth.

4. In a compound engine, the combination ofa cylinder, a hollow pistonmounted therein, a plunger working in said piston, a valve mechanism foradmitting steam into the'highpressure chamber and for allowing steam toexpand from the high-pressure chamber into the low-pressure chamber,extensions carried by the cylinder and to which said plunger isconnected, bifurcated arms on the piston working in and guided by saidextensions, an engine-frame connected to said extensions, a shaft insaid frame, and connections between the shaft and said bifurcated arms,substan tially as set forth.

This specification signed and witnessed this 22d day of September, 1898.

MARGY L. WHITFIELD.

WVitnesses:

J. G. MOMICHAEL, T. H. MoMIcHAnL.

